Development of a High Temperature CO2 Sorbent Based on Hydrotalcite for a H2-Rich Syngas Production

To adapt hydrotalcite-based sorbents (also known as layered double hydroxides—LDHs) to high-temperature CO2 sorption compatible with tar steam reforming, the addition of CaO was investigated, maintaining LHDs porosity and accessibility but mostly assuring stability during sorption/desorption cycles. In co-precipitation synthesis, investigated parameters are (i) various interlayer anions different sizes valences (carbonate, oxalate, stearate); (ii) pH values; (iii) Mg/Ca molar ratios. The characterization these modified LDHs by TGA, XRD, N2 adsorption, SEM, capacity, (cyclic TGA) allowed understanding effect synthesis highlighted oxalate use anion. After calcination sorbent Mg/Ca/Al ratio = 1/2/1, typical LDH sand roses were formed both carbonate anions: this former exhibited highest capacity sites at 600 °C, higher than pure CaO. However, best cycles obtained from 1.5/1.5/1 10 for which comparable results reached. For two samples, observed macro-porosity associated specific surface area pore volume.